Squamous cell carcinoma of the thyroid gland: primary or secondary disease?

To diagnose primary and secondary squamous cell carcinoma of the thyroid with ultrasound malignancy risk stratification

Objectives

This study aimed to investigate the clinico-ultrasound features of primary squamous cell carcinoma of the thyroid (PSCCT) and secondary SCCT (SSCCT) and evaluate the accuracy of fine needle aspiration (FNA) recommendation for SCCT with American College of Radiology-Thyroid Imaging and Reporting Data System (ACR-TIRADS) and Chinese-TIRADS (C-TIRADS).

Materials and methods

We retrieved 26 SCCT patients (11 PSCCT, 15 SSCCT) from our hospital's pathology database (5,718 patients with thyroid malignancy) over 23 years. Medical records and ultrasound data of the 26 patients with 27 SCCTs were analyzed retrospectively, and each SCCT focus was categorized based on the two TIRADSs.

Results

For 26 patients (21 males, 5 females) with an age range of 42-81 years, rapidly enlarging thyroid/neck nodules (18/26, 69.2%), dysphagia (7/26, 26.9%), hoarseness (6/26, 23.1%), dyspnea (5/26, 19.6%), cough (4/26, 15.4%), neck pain (2/26, 7.7%), B symptoms (2/26, 7.7%), and blood in sputum (1/26, 3.8%) were presented at diagnosis. Five asymptomatic patients (5/26, 19.2%) were detected by ultrasound. Hoarseness was more common in PSCCT (5/11, 45.5%) than in SSCCT (1/15, 6.7%) (P=0.032). For 27 SCCTs with a mean size of 3.7 ± 1.3 cm, the ultrasound features consisted of solid (25/27, 92.6%) or almost completely solid composition (2/27, 7.4%), hypoechoic (17/27, 63%) and very hypoechoic echogenicity (10/27, 37%), irregular/lobulated margin with extra-thyroidal extension (27/27, 100%), taller-than-wide shape (13/27, 48.1%), punctate echogenic foci (6/27, 22.2%), hypervascularity (23/27, 85.2%) and involved neck lymph (13/26, 50.0%). A total of 27 SCCTs were evaluated as high malignancy risk stratification (≥TR4 and 4B) by the two TIRADSs and recommended FNA in 96.3-100% (26/27, 27/27). Pathologically, more than half of PSCCTs (7/12, 58.3%) and a quarter of SSCCTs (4/15, 26.7%) were poorly differentiated, while moderately and well-differentiated grades were observed in 5 PSCCTs and 11 SSCCTs (P=0.007). Thirteen patients (50.0%) underwent surgery with radical operation in 5 cases (5/13, 38.5%).

Conclusion

SCCT is an extremely rare and aggressive malignancy with a male predominance. PSCCT and SSCCT had similar clinical and ultrasound features except for tumor differentiation and the symptom of hoarseness. SCCT showed a high malignancy risk stratification in ACR-TIRADS and C-TIRADS, with a high rate of FNA recommendation.

Progress in diagnosing and treating thyroid squamous cell carcinoma under the 5th edition of WHO classification

Squamous cell carcinoma of the thyroid (SCCT) is a rare thyroid gland malignancy, with only a few hundred cases reported in the literature, mostly as case reports or small sample studies. In the previous WHO classification, squamous cell carcinoma of the thyroid was defined as a carcinoma composed entirely of squamous cells without differentiated carcinoma components. It was once included in the WHO tumor classification separately. However, the 2022 WHO classification of squamous cell carcinoma of the thyroid was reclassified as a morphologic subtype of anaplastic thyroid carcinoma (ATC). The squamous cell carcinoma pattern is similar to the other histologic types of ATC, but the phenotype associated has a poorer prognosis. The typical clinical manifestation of this condition is a cervical mass, accompanied by indications and symptoms of compression on adjacent structures such as the esophagus and trachea in advanced stages. Secondary squamous cell carcinoma of the thyroid may occur due to the spread of squamous carcinoma of the larynx or esophagus or distant metastases from other sites. Diagnosis of squamous cell carcinoma of the thyroid includes neck Ultrasound (US), Computed Tomography (CT) or Magnetic Resonance Imaging (MRI), puncture tissue biopsy, and full endoscopy to identify metastatic lesions from the nasopharynx, oropharynx, hypopharynx, larynx, esophagus, or bronchi and to help with the initial staging of the tumor. Current treatment modalities include surgery, radiotherapy, chemotherapy, or a combination. Because of the poor prognosis of patients with this disease, the short survival period, usually less than one year, and the difficulty of preoperative diagnosis, this article reviews the epidemiological features, origin, clinical features, pathological features, and differential diagnosis to improve the diagnosis and treatment of this disease by clinicians.

Anlotinib combined with Sintilimab is win-win cooperation for primary squamous cell carcinoma of the thyroid: A case report and literature review

Background

Primary squamous cell carcinoma of the thyroid (PSCCT) is a rare malignant tumor. The incidence rate of PSCCT is less than 1%. However, the diagnosis and treatment of PSCCT are limited. Surgical resection is considered to be one of the few effective intervention methods. In this article, we reported a case of taking tyrosine kinase inhibitors (TKIs) combined with immune checkpoint inhibitors (ICIs) for PSCCT.

Case summary

An 80-year-old male was admitted to our hospital with dyspnea, cough, wheezing, and hoarseness for a giant thyroid mass. He underwent bronchoscopy and tracheal stent implantation to alleviate the respiratory obstruction. Then he accepted right partial thyroid and right lymph node biopsy. Postoperative pathology revealed squamous cell carcinoma. Subsequently, he underwent an endoscopy to exclude upper gastrointestinal squamous cell carcinoma. Finally, he was diagnosed with PSCCT. The patient was tentatively treated with a combination of Anlotinib and Sintilimab. After two courses, the tumor volume significantly reduced in MRI images and shrank further after five courses of combined treatment. Unfortunately, the patient died of fulminant liver failure and autoimmune liver disease after 5-month-treatment.

Conclusion

TKIs combined with ICIs may be an effective and novel way for PSCCT treatment, but immune-related complications, especially liver damage, should be cared.

Primary squamous cell carcinoma of the thyroid treated with concurrent chemoradiation and palliative immunotherapy: a case report

BACKGROUND

Primary squamous cell carcinoma of the thyroid is a very rare malignancy with aggressive growth and poor prognosis. There is currently no consensus for treatment modality, however, most patients with primary squamous cell carcinoma of the thyroid are treated with surgery and adjuvant chemoradiation.

CASE PRESENTATION

We report a rare case of primary squamous cell carcinoma of the thyroid in a 68-year-old White male who underwent chemoradiation and palliative immunotherapy after declining surgery. He was treated with intensity-modulated radiation therapy to 70 Gy in 35 fractions, with concurrent carboplatin-paclitaxel and palliative pembrolizumab. Local thyroid disease recurrence occurred at 6 months post-chemoradiation, and the patient died at 16 months post-chemoradiation.

CONCLUSIONS

This is the first case report demonstrating the use of pembrolizumab as palliative therapy for primary squamous cell carcinoma of the thyroid. Our study also highlights the importance of chemoradiation in decreasing primary mass size and immunotherapy in preventing metastatic disease progression.

Clinical analysis of 13 cases of primary squamous-cell thyroid carcinoma

Objective

To analyze the clinical features, ultrasonographic manifestations, pathological features, treatment and prognosis of primary thyroid squamous cell carcinoma (PSCTC) and summarize the experience in diagnosis and treatment of this condition.

Methods

A retrospective analysis was conducted on patients who were admitted to Zhejiang Cancer Hospital from 2007 to 2021 due to thyroid nodules or thyroid malignant tumors that were ultimately confirmed by postoperative pathology as primary thyroid squamous cell carcinoma. We summarize the general situation, clinical information, laboratory examination, ultrasonic image characteristics, pathological examination, clinical treatment and prognosis of the patients.

Results

PSCTC is most often seen in older men and progresses rapidly. In laboratory tests, some patients had elevated levels of tumor markers (CA199, squamous cell carcinoma antigen level), thyroglobulin levels and tumor-related substances, but all these indicators lacked specificity. The ultrasound features of PSCTC are mainly hypoechoic, hard, substantial nodules with gross borders and a grade 1-2 blood flow signal, sometimes with signs of necrosis and calcification. In terms of treatment, PSCTC is mainly surgically resected, though some patients in this study underwent iodine-131 radiation therapy, local radiotherapy, and chemotherapy with unclear results. None of the patients survived for very long after treatment, but the prognosis of patients with highly differentiated squamous carcinoma was significantly better than that of patients with poorly differentiated squamous carcinoma. Papillary thyroid carcinoma may be one of the causes of PSCTC.

Conclusion

PSCTC is a malignant tumor with high malignancy and rapid clinical progression. Treatment options are mainly based on surgical resection and can be supplemented with radiotherapy and chemotherapy, but there is still a lack of a standardized treatment management system, and more cases and reports are needed to accumulate data.

Squamous Differentiation in the Thyroid: Metaplasia, Neoplasia, or Bystander?

Background. Squamous differentiation within the thyroid is seen in a variety of settings. Squamous epithelium is non-native to the thyroid, and its debated origins span reactive metaplasia and developmental/embryologic remnants. Despite a lack of clarity as to its evolution, squamous epithelium may be associated with both neoplastic and non-neoplastic processes. Methods. Thyroid pathology reports spanning a 30-year period were reviewed for terms indicating squamous features. Associated diagnostic and clinical information was collated. Results. Four hundred and twenty seven of 17,452 (2.4%) thyroid surgical pathology cases during this period utilized terminology indicating squamous differentiation including 243 malignant (58%) and 178 benign (42%) diagnoses. There were 111 (26%) primary thyroid malignancies with squamous differentiation, 116 (28%) malignancies of non-thyroid origin including local extension from nearby cancers, and 16 (4%) malignancies of uncertain primary. Most benign lesions were non-neoplastic (84%). The minor subset representing benign neoplasia was interpreted as secondary reactive changes. Conclusion. While squamous differentiation is seen routinely in the thyroid, it is most commonly reported in malignancy. For primary thyroid malignancies reported to demonstrate a squamous component, biologically aggressive tumors were overrepresented. Available evidence suggests that multiple pathways may contribute to the presence of squamous epithelium in the thyroid including metaplasia of mature follicular cells, development from established embryonic remnants, or inception in putative, incompletely characterized stem-like cells. Our retrospective review presents an institutional landscape from which further investigation into the frequency and unique histologic and molecular context of intrathyroidal squamous differentiation as a driver or terminal event in thyroid pathophysiology.

Anaplastic spindle cell squamous carcinoma arising from classical papillary thyroid carcinoma with foci of columnar cell component: A case report

We report a case of the anaplastic spindle cell squamous carcinoma(SC) arising from classical papillary thyroid carcinoma(PTC) with foci of columnar cell component in a 69-year-old Chinese woman. The tumor of the right lobe was composed of spindle cell SC and PTC. Histologically,the spindle cell SC were arranged into bundles with marked cellular atypia, nuclear pleomorphism and more mitotic figures. The tumor of the left lobe was a PTC without any SC elements,which was composed of two components, namely classical and columnar cell variants PTC. The columnar cell elements occupied more than 20 % of PTC, which showed striking stratification of nuclei with no characteristic nuclei for the classical type of PTC. The patient has not received any other treatment after radical surgery. She had no tumor recurrence and other complications 13 months after operation. Only classical PTC but not columnar cell PTC and SC had been identified in 7 out of 50 excised cervical lymph nodes. In order to clarify the origin of PTC and spindle cell SC, we performed the BRAF^V600E(c.1799 T > A) mutational analysis. The results of molecular analysis showed that BRAF^V600E(c.1799 T > A) mutation existed in both components, which further confirmed that spindle cell SC was transformed from PTC.

Primary squamous cell carcinoma of the thyroid: a case report

Primary squamous cell carcinoma of the thyroid (PSCCT) is a rare and rapidly progressive malignancy that carries a poor prognosis. PSCCT is easily misdiagnosed as acute thyroiditis or as another thyroid malignancy. We have reported a 76-year-old woman who presented with progressive neck pain for 1 month. Thyroid function tests revealed subclinical thyrotoxicosis. Ultrasound disclosed a solid nodule with calcification in the right thyroid lobe. Laboratory findings included neutrophilic leukocytosis and an elevated erythrocyte sedimentation rate. The patient's condition was diagnosed as subacute thyroiditis, and she was treated with cefixime and ibuprofen. However, her treatment response was poor. She was then treated with oral prednisone. Her neck pain gradually resolved. The patient subsequently developed dysphagia, choking, dyspnea, and dysphonia with an insidious onset. Further examinations including computed tomography and painless gastroscopy revealed that the volume of the thyroid gland had increased significantly, extending to the anterior superior mediastinum. The trachea and esophagus were stenotic because of external compression. Partial thyroidectomy and tracheotomy were performed under extracorporeal membrane oxygenation. The diagnosis of PSCCT was established via histopathology and immunohistochemistry.

A characterization and prognosis prediction model for primary squamous cell carcinoma of the thyroid

Background

Primary squamous cell carcinoma of the thyroid (PSCCTh) is a sporadic malignancy arising from the thyroid gland. The factors that affect treatment and survival in patients with PSCCTh remain unclear. Our study aims to characterize PSCCTh and establish a prognosis prediction model for patients with PSCCTh.

Methods

Clinical data and follow-up information for 277 patients from 1973 to 2016 were collected from the Surveillance, Epidemiology, and End Results Program (SEER) 18-registry database (RRID:SCR_003293). Univariate and multivariate Cox proportional hazards analyses and nomogram modeling of potential prognostic factors were conducted.

Results

Among the collected patient cases, 57% were female and 43% were male. The median survival of all cases was 6 months; by gender, median survival was 5 and 8 months in the female and male groups, respectively. Univariate and multivariate Cox proportional hazards analyses revealed that age, extent of disease (EOD), T stage, N stage, and treatment were independent prognostic indicators for overall survival (OS) and disease-specific survival (DSS) in patients with PSCCTh. In addition, it was confirmed that the established nomogram model had good consistency and discrimination for PSCCTh prognosis as measured by the concordance index (C-index), area under the receiver operating characteristic (ROC) curve (AUC), and calibration curves.

Conclusions

Our study indicates that age, EOD, T stage, N stage, and treatment may correlate with OS and DSS in patients with PSCCTh. Importantly, our nomogram prediction model, constructed using parameters including age, T stage, N stage, and treatment, may assist physicians in evaluating patients' prognoses and providing precise therapy for PSCCTh.

Primary squamous cell carcinoma of the thyroid gland successfully treated with surgical resection and adjuvant chemoradiotherapy

A 57-year-old woman presented with a 3-month history of an enlarging thyroid mass causing breathlessness and dysphagia. Cross-sectional imaging showed a thyroid tumour infiltrating the trachea and abutting the oesophagus. She underwent panendoscopy, total thyroidectomy and planned tracheal resection, but due to intraoperative findings, a staged procedure was planned instead. Histological analysis revealed a poorly differentiated squamous cell carcinoma (SCC) which was positive on paired box gene 8 (PAX8) immunostaining, suggesting a diagnosis of primary thyroid SCC. She subsequently underwent total laryngectomy and bilateral neck dissections followed by radiotherapy with concurrent cisplatin chemotherapy. The patient remains disease-free 22 months after treatment. Median overall survival is 10 months for macroscopically completely resected tumours. PAX8 immunostaining is a novel technique which helps with the diagnostic challenge of distinguishing between primary thyroid SCC and SCC metastatic to the thyroid from extrathyroidal sites. Complete surgical resection with adjuvant chemoradiotherapy may result in a favourable outcome despite conflicting reports in the literature.

Primary thyroid squamous cell carcinoma: a challenging management problem

Primary thyroid squamous cell carcinoma (SCC) is a rare and highly aggressive cancer. Diagnostic work-up encompasses cervical ultrasonography, tissue biopsy and CT scan. Surgery, radiotherapy and chemotherapy are the available treatment modalities. With a mean survival rate of 7 months reported in the literature, our patient is alive 2 years after successful treatment of her advanced primary thyroid SCC with surgery and radiotherapy.

Prognostic Characteristics of Primary Squamous Cell Carcinoma of the Thyroid: A National Cancer Database Analysis

BACKGROUND

Primary squamous cell carcinoma of the thyroid (ThySCC) is a rare cancer, primarily described only in case reports. We aimed to characterize the prognosis of ThySCC and compare its oncologic behavior to other thyroid malignancies.

METHODS

The National Cancer Database was queried to identify patients with ThySCC, papillary, tall cell variant, poorly differentiated (PDTC), and anaplastic (ATC) subtypes of thyroid cancer treated from 2004 to 2015. Demographics, tumor characteristics, and treatments were compared by tumor type and assessed to identify independent predictors of overall survival (OS).

RESULTS

Of 123,684 patients included, 314 had ThySCC. ThySCC patients had a 5-year OS of 17.7%, more closely resembling ATC (8.3%) than PDTC or PTC. ThySCC and ATC patients had similar demographics, except ThySCC patients who were younger (68.0 vs. 70.2 years, p < 0.01). ThySCC tumors were smaller (mean 53.5 ± 45.7 vs. 69.5 ± 75.2 mm) with less frequent extrathyroidal extension (ETE) (64.0% vs. 73.8%), lymphovascular invasion (8.3% vs. 12.3%), and positive margins (22.0% vs. 28.3%) compared to ATCs (p < 0.05). ETE [HR 3.1 (95% CI 1.5-6.4), p < 0.05] and lymph node metastases [HR 2.2 (95% CI 1.2-4.0) p < 0.05] were independently associated with worse OS for ThySCC patients. Both ThySCC and ATC patients had similar surgical success rates, with R1 resection possible in 37.3% versus 35.0% of patients, respectively (p < 0.05). However, in contrast to ATC patients, adjuvant therapy was not associated with improved OS for ThySCC patients after complete resection.

CONCLUSIONS

ThySCC has a poor prognosis, similar to ATC, but with fewer aggressive features and no apparent survival benefit with adjuvant therapy after complete macroscopic surgical resection.

A Primary Squamous Cell Carcinoma of the Thyroid Presenting as the Anaplastic Thyroid Carcinoma: A Case Report

Background: Primary squamous cell carcinoma of the thyroid (PSCCT) is an uncommon malignancy that is difficult to diagnose and differentiate. There is no consensus for the early clinical, radiological, or ultrasonic identification of PSCCT before pathological changes are observed in patients. There is also no suitable treatment due to the absence of a definite diagnosis. Case Presentation: A 76-year-old female patient complained about a rapidly growing cervical mass, dyspnea, dysphagia, and a change in her voice. Based on the results of thyroid ultrasound, fine-needle aspiration, and plain and enhanced CT, the patient was initially diagnosed with anaplastic thyroid carcinoma (ATC). Thereafter, we removed the mass that was the patient's main complaint. The gross examination of the patient's symptoms also supported our previous diagnosis. However, her disease was finally diagnosed as PSCCT, according to the histopathology and immunohistochemistry findings of the mass. Conclusion: Our case highlights the need for a comprehensive framework in the management of PSCCT. The more auxiliary examinations (e.g., ultrasonographic, radiology, or biopsy examinations) we take, the more likely we are to identify this disease. Immunohistochemistry is currently the preferred examination for the diagnosis of PSCCT, while surgical resection combined with radio-sensitizing therapy and adjuvant chemotherapy is the main treatment method for PSCCT.

Primary squamous cell carcinoma of thyroid with a novel BRAF mutation and High PDL-1 expression: A case report with treatment implications and review of literature

Primary squamous cell carcinoma of thyroid (SCC-T) is an extremely rare, aggressive neoplasm with median survival of 9 months. Pure squamous morphology with absence of other cell types is required for diagnosis of SCC-T. Clinically, SCC-T behaves like anaplastic thyroid carcinoma (ATC) showing rapid growth, and extra thyroidal extension. We report a 91-year-old woman presenting with an enlarging thyroid mass and accompanying dysphagia and hoarseness. Fine needle aspiration revealed hypercellular specimen with large, pleomorphic, malignant cells. Intraoperative assessment revealed an inoperable tumor involving both thyroid lobes and extensively infiltrating surrounding soft tissues. A subtotal thyroidectomy was performed. Histology revealed squamous cell carcinoma replacing native thyroid tissue and infiltrating adjacent skeletal muscle. Lymphovascular and perineural invasion were present. Immunohistochemistry showed tumor cells positive for CK5-p40, Pax-8, TTF-1 and negative for thyroglobulin. P53 expression by IHC was high and Ki-67 proliferation index was > 90 %. (Next generation sequencing revealed a novel BRAF mutation (BRAF c.1799 T > A; 1801_1812del) along with TP53 and TERT mutations. PDL-1 immunohistochemistry showed positive expression in tumor cells (>80%), making patient also amenable to anti-PDL-1 immunotherapy. Patient was treated with BRAF inhibitor therapy with initial relief but eventually was put on hospice care due to increasing intolerance to therapy. This case represents a rare thyroid malignancy with a unique molecular signature consisting of a novel BRAF mutation [previously not described in SCC-T or ATC], associated with TERT-TP53 mutations. Further, importance of PDL-1 testing as a prognostic marker and as a guide to immunotherapy in refractory tumors is discussed.

Prevalencia de tumores metastásicos en la glándula tiroides. Revisión sistemática y metanálisis

Introducción y objetivo: Los tumores metastásicos en la glándula tiroides complican el diagnóstico, el tratamiento y el pronóstico del paciente. El objetivo es conocer la prevalencia de las metástasis en la glándula tiroides referida en la literatura médica y los tumores primarios que con más frecuencia metastatizan en la glándula tiroides. Método: Se realizó una revisión bibliográfica sistemática en las bases de datos de PubMed, La Biblioteca Cochrane y Scopus. Los artículos seleccionados se dividieron en dos grupos, series clínicas de pacientes en los que se hallaron metástasis en tiroides (grupo A) y series de hallazgos de metástasis en tiroides en autopsias (grupo B). Se realizó metanálisis de prevalencia para cada grupo de artículos siguiendo el modelo de efectos aleatorios. Resultados: La prevalencia en cada grupo con su índice de confianza al 95% fue 0.00479 (0.002-0.007) para el grupo A y 0.0362 (0.014-0.059) para el grupo B. La prevalencia de metástasis halladas en autopsias fue 7,58 veces mayor que en los estudios clínicos. En el grupo A la edad media fue 60.82 y en el grupo B 57.20. En ambos grupos las metástasis halladas en tiroides fueron más frecuentes en el sexo femenino. La localización del tumor primario fue diferente en ambos grupos, en el grupo A fue el cáncer de riñón y en el grupo B el cáncer de mama. La variabilidad de la prevalencia de metástasis en tiroides en los diferentes artículos de ambos grupos hace que este estudio tuviese una alta heterogeneidad (índice I2 y Q). Los funnel plot de ambos grupos indicaron alto sesgo de publicación. Discusión: La diferente prevalencia entre series clínicas y autopsias puede implicar que la detección de metástasis en tiroides en la clínica está infradiagnosticada. La razón de esto podría ser que las metástasis intratiroideas se presentan de forma asintomática siendo diagnosticadas como hallazgo casual en autopsias. En otras ocasiones se presentan como un nódulo tiroideo años después del tumor primario, lo que condiciona el diagnóstico. Conclusiones: La prevalencia de metástasis en tiroides es superior en las series de autopsias que en series clínicas (hasta 6.67 veces más frecuente en nuestro estudio). Las metástasis intratiroideas probablemente están infradiagnosticadas por cursar sin clínica siendo diagnosticadas como hallazgo casual en autopsias. Los tumores primarios más frecuentes fueron el riñón (series clínicas) y la mama (series de autopsias).

Squamous cell carcinoma of the thyroid gland in an elderly female presenting as a rapidly enlarging thyroid mass

•

Squamous cell carcinoma of the thyroid gland is an extremely rare tumor.

•

It may be primary tumor within the thyroid gland or as a component of anaplastic or undifferentiated tumors.

•

The tumor has a very aggressive clinical behavior with a median survival of few months.

Background

Squamous cell carcinoma of the thyroid gland is an extremely rare tumor with a very aggressive clinical behavior and poor prognosis. The tumor may arise as a primary tumor within the thyroid gland or as a component of anaplastic or undifferentiated thyroid tumors.

Case presentation

A 70-year-old lady with history of long standing multinodular goiter presented with progressive enlargement of a midline nodule for 3 months which was associated with dyspnea and dry cough. The mass was hard and fixed. The voice was normal, other parts of the general examination were unremarkable. Fine needle aspiration was done for the mass which revealed malignant cells mixed with inflammatory cells. During surgery there was a hard and fixed mass arising from the isthmus of the thyroid gland that was locally invading, complete excision was not possible, debulking was done. Histopathology showed moderately differentiated squamous cell carcinoma of the thyroid gland. The tumor underwent local progression 6 months later and the patient was sent for radiotherapy.

Conclusion

When thyroid tumor is advanced at time of diagnosis, radiotherapy is the main form of treatment which may induce reduction in the size of the tumor and decrease pain, radiotherapy may also be given on neoadjuvant bases which may render resection possible in some patients. The tumor is usually not responsive to chemotherapy. The overall survival is uniformly poor regardless of the primary form of treatment, the median survival of the patients from the time of diagnosis is few months in most cases.

A case report of papillary thyroid carcinoma dedifferentiated to squamous cell carcinoma presenting as a lung metastasis: A potential diagnostic pitfall

Papillary thyroid carcinoma (PTC) tall cell variant (TCV) with squamous dedifferentiation is a rare entity. We present a case of 90-year-old woman who initially had a 2.8 cm conventional PTC in right lobe of thyroid who, couple decades later, had metastatic dedifferentiated PTC to right neck lymph nodes level II and IV with tall cell features; to right level IV and V lymph nodes with tall cell and squamous components, which recently presented exclusively as squamous cell carcinoma (SCC) metastasizing to lung. The squamous component in the lymph node and SCC in the lung were both positive for squamous marker p63 and PTC markers TTF1, PAX-8 and BRAF V600E while negative for thyroglobulin and p16. The papillary component was positive for TTF-1, BRAF V600E and P63 (majority); negative for thyroglobulin and p16. Final diagnoses were rendered based on combination of cytological features and immunohistochemical profiles. This report highlights the utilization of current biomarkers to distinguish between metastatic dedifferentiated PTC with squamous features and primary lung SCC, as well as the importance of recognizing this rare entity.

De-differentiation of papillary thyroid carcinoma into squamous cell carcinoma in an elderly patient: A case report

RATIONALE

The unpredictability of thyroid cancer can be striking, as the disease may rapidly progress to death in some individuals. Herein, we reported a rare case of aggressive papillary thyroid cell carcinoma (PTC) in an elderly patient de-differentiated into squamous cell carcinoma (SCC).

PATIENT CONCERNS

We describe a case of a 79-year-old Thai woman presented with hoarseness and neck mass for 2 months and she had been diagnosed with a 3-cm papillary thyroid carcinoma (PTC) in the right side of the thyroid gland. Later on PTC de-differentiated into SCC within 3 years after initial presentation.

DIAGNOSIS

De-differentiation from papillary thyroid carcinoma to squamous cell carcinoma.

INTERVENTIONS

The patient underwent a total thyroidectomy at the initial hospital and received high dose radioactive iodine (RAI) treatment at our hospital 1 month following the surgery and then was lost to follow-up. Two years later she came back with new development of right solid-cystic neck mass which was found to be recurrent PTC. A radical neck dissection was done and another high dose RAI treatment was given. However, she developed recurrent mass with tenderness at the site above previous solid cystic mass 6 months later. Re-exploration of the neck mass revealed an inflamed midline mass 2 cm with enlarged right lateral cervical lymph nodes.

OUTCOMES

A histopathological examination of the midline neck mass showed poorly differentiated SCC with lymphatic invasion. The intermingling of two morphologically distinct tumors, a typical PTC and a poorly differentiated SCC, had been identified in 1 out of 14 excised cervical lymph nodes. The patient underwent external beam radiation without chemotherapy. She is still in stable condition at 18 months post-treatment.

LESSONS

This case clearly demonstrated that SCC transformed from a pre-existing PTC. The clinician should consider a possible transformation of papillary thyroid cancer into more aggressive histological types in elderly patients who present with rapidly progressive clinical behavior. However, some patients could have long-term survival if the tumor did not transform into anaplastic thyroid cancer.

Primary squamous cell carcinoma (PSCC) of the thyroid: a case report and review of the literature

Primary squamous cell carcinoma (PSCC) is a rare neoplasm of the thyroid with a very poor prognosis. We report a case of a 42-year-old woman with occasionally found mass in the right anterior area of the neck. After a total thyroidectomy, histopathology and immunohistochemistry tests confirmed primary squamous cell carcinoma of the thyroid with the exclusion of all other possible primary tumor locations. 5 months later, PET scan discovered abnormality in right cervical lymph nodes with a fine needle aspiration confirming to be tumor recurrence. After a modified radical neck dissection was performed with pathological results of the neoplasms being PSCC of the thyroid origin, a full course consecutive radiotherapy was then followed. Due to a prompt diagnosis and the complete dissection of primary tumor and metastatic lymph nodes, no recurrence was observed at the follow-up visits. Comparing to the published cases of PSCC of the thyroid, our paper stated a whole process of diagnosis and standardized treatment, together with classical matched figures of pre-op examinations and dissected specimen. Furthermore, a review of the present literatures summarized the diagnosis, treatment and prognosis of thyroid PSCC. The management of PSCC requires a multi-disciplinary approach.

Treatment optimization and prognostic considerations for primary squamous cell carcinoma of the thyroid

Background

Primary squamous cell carcinoma of the thyroid (PSCCT) is a rare aggressive malignancy that usually presents in an advanced stage and has a poor prognosis. Our study aimed to investigate the clinical characteristics, treatment, and prognosis of PSCCT.

Methods

We retrospectively reviewed the medical information of patients with PSCCT diagnosed from January 2006 to May 2018 at Xiangya Hospital. Survival analysis was conducted using the Kaplan-Meier method, and Log-Rank tests were performed for statistical testing.

Results

We identified 12 patients with PSCCT (nine males and three females), accounting for only 0.19% of all thyroid cancer diagnosed during this time period. The median age of these patients was 59.5 years old and their symptoms included neck masses (n=5), hoarseness (n=2), dyspnea (n=1), dysphagia (n=1) and neck pain (n=1). Four patients were in stage IVA, five were stage IVB, and three patients were stage IVC. Six patients underwent comprehensive treatment (surgery + radiotherapy or surgery + radiotherapy + chemotherapy) and the remaining patients received radiotherapy and/or chemotherapy. The 6-month survival rate was 66.7%, compared to a 1-year survival rate of 25.0%, with a median overall survival time was 10.5 months. Kaplan-Meier analysis showed that the comprehensive treatment was superior to radiotherapy and/or chemotherapy (P=0.003).

Conclusions

PSCCT is a rare type of thyroid cancer that is highly invasive and has a poor prognosis. We show that a comprehensive treatment plan can significantly improve patient survival.

The Utility of Immunohistochemistry in Differentiating Metastatic Primary Squamous Cell Carcinoma of the Thyroid from a Primary Lung Squamous Cell Carcinoma

Primary squamous cell carcinoma of the thyroid gland (PSCCTh) and anaplastic thyroid carcinoma with extensive squamous differentiation are rare entities which pose a diagnostic challenge in determining the primary site when presented as metastases. The difficulty in confirming a thyroid primary is further compounded by the aggressive nature of these tumours which frequently present at advanced stages. We present a case in which the patient presented with a thyroid mass and a lung mass simultaneously. The risk of misinterpreting the site of primary tumour as lung is greatly increased because squamous cell carcinoma of lung is much more common than its thyroid counterpart. This case highlights the effectiveness of PAX-8 stain in determining the primary site of tumour when squamous cell carcinoma is found in both lung and thyroid gland.

Primary Squamous Cell Carcinoma in the Thyroid Gland: A Population-Based Analysis Using the SEER Database

OBJECTS

To evaluate prognostic factors and treatment outcomes of primary squamous cell carcinoma in thyroid (PSCCTh) over the past decades using a large national database.

METHODS

All patients diagnosed with PSCCTh between 1973 and 2015 were identified with the Surveillance, Epidemiology, and End Results Program (SEER) 18-registry database. Relevant clinical data were collected, and prognostic factors of overall survival (OS) and disease-specific survival (DSS) were analyzed.

RESULTS

This cohort study included 242 patients, accounting for 0.12% of all primary thyroid carcinomas from 1973 to 2015 nationwide. Of the patients with PSCCTh, 75% were older than 60 years at diagnosis. Patient age older than 60 years (HR 2.242, 95% CI 1.367-3.676, P = 0.001) and a tumor size larger than or equal to 50 mm (HR 1.479, 95% CI 1.011-2.165, P = 0.044) were independent negative prognostic factors. The univariate analysis suggested that the morphological subtype (OS, P = 0.033; DSS, P = 0.048), clinical treatment modality (OS, P < 0.0001; DSS, P < 0.0001), and T stage (OS, P = 0.004; DSS, P = 0.001) were important predictive factors for OS and DSS. In contrast, gender, race, year of diagnosis, geographic location, N stage, and M stage were not prognostic factors.

CONCLUSIONS

PSCCTh is a rare malignancy with an aggressive nature and poor prognosis. Survival is predicted by the treatment modality, patient age, T stage, tumor size, and morphological subtypes. This study showed that early diagnosis and complete surgical resection plus adjuvant radiation therapy were associated with a better outcome.

Primary Squamous Cell Carcinoma of the Thyroid

Background: Primary squamous cell carcinoma of the thyroid (PSCCT) is a rare malignancy of the head and neck, with fewer than 60 cases reported in the literature. We report a case of PSCCT and provide a brief review of the literature. Case Report: A 66-year-old female with a history of a hemithyroidectomy for a benign thyroid lesion presented with 3 months of progressively worsening compressive symptoms and shortness of breath. Physical examination revealed right-sided thyromegaly and right-sided true vocal fold immobility. Preoperative imaging with ultrasound and computed tomography scan confirmed an enlarged right thyroid, as well as right anterior cervical lymphadenopathy, subglottic stenosis, and bilateral pulmonary nodules. Fine needle aspiration of the thyroid was suggestive of carcinoma. Intraoperative findings of gross tracheal invasion during a planned completion thyroidectomy prompted limited resection and impromptu tracheotomy. Histopathologic and immunohistochemical evaluation confirmed a squamous cell carcinoma of thyroid origin. Further oncologic workup with core lung biopsy and positron emission tomography scan demonstrated metastasis to the lung and cervical spine. Palliative chemotherapy was begun, but the patient died 1 week into therapy. Conclusion: PSCCT is a rare but aggressive malignancy of the head and neck. Histopathologic and immunohistochemical evaluations are essential for diagnosis. While locoregional surgery and radiation therapy may improve the length of survival, the prognosis of patients with PSCCT is poor. Physicians should be mindful of this unique but deadly disease process, as early diagnosis and rapid treatment initiation are essential to optimize treatment outcomes.

Identification of Human Cutaneous Squamous Cell Carcinoma Cancer Stem Cells

Epithelia are under constant threat from environmental carcinogens and none more so than squamous epithelia, which form the outermost linings of our bodies. Hence malignancies of squamous epithelia are collectively the most common cancer type and with the highest mortality, despite a constant cell turnover and only relatively rare long-lived adult tissue stem cells. Genetic analysis from SCC whole genome sequencing reveals commonality in mutated genes, despite various etiological factors. Most SCC types have been shown to exhibit hierarchical growth, in which a high frequency of cancer stem cells is associated with poor prognosis. For human cutaneous SCC (cSCC), we have shown that cancer stem cells express CD133 and that this population can recreate tumor heterogeneity in a novel in vivo model. CD133+ cSCC cells is small subset of tumor cells (~1%) in the outer layer of cSCC that are highly enriched for tumor-initiating capacity (TIC) (~1/400) compared to unsorted cSCC cells (~1/10⁶). Xenografts of CD133+ cSCC recreated the original cSCC tumor histology and organizational hierarchy, while CD133- cells did not. Only CD133+ cells demonstrated the capacity for self-renewal in serial transplantation studies. Hence, cSCC has the potential to be the ideal model in which to study SCC biology.

Not all neck mass fine-needle aspirations with squamous cells are squamous cell carcinoma; report of a case of recurrent thyroid carcinoma with papillary and squamous components

We report a case of a 65-year-old female who had a total thyroidectomy 12 years ago for papillary thyroid carcinoma (PTC) who presented with a recurrent thyroid bed mass. Fine-needle aspiration biopsy yielded malignant cells, consistent with squamous cell carcinoma (SCCa). Surgical resection was performed, and histologic evaluation of the mass showed mixed PTC and SCCa. The tumor cells were positive for BRAF V600E mutation. Thyroid carcinomas with admixed papillary carcinoma and SCCa are rare and are associated with aggressive behavior, high rates of metastasis, and poor outcomes. Although SCCa presenting as a neck mass is relatively common, clinical history and appropriate workup are essential for accurate diagnosis and determination of origin.

Immunohistochemical Features of Primary Pure Squamous Cell Carcinoma in the Thyroid: An Autopsy Case

Primary squamous cell carcinoma (SCC) in the thyroid is extremely rare and has been reported in < 1% of all thyroid cancer cases. Primary SCC in the thyroid was thought to be a transitional form derived from adenocarcinomas; therefore, the majority of reported cases have focused on the conjunction with other histological adenocarcinomas. A 73-year-old male presented to our hospital with bilateral vocal fold palsy and an anterior neck mass. Ultrasound sonography revealed a bulky tumor in the thyroid and bilateral cervical lymphadenopathy. We performed fine-needle aspiration cytology from the thyroid tumor, which revealed SCC. Positron emission tomography/computed tomography showed distant metastases in the lungs, mediastinal lymph nodes, and vertebra. We diagnosed the patient as having stage IVC SCC in the thyroid and administered weekly paclitaxel. Four and a half months after treatment initiation, the tumor progression resulted in aspiration pneumonia, which proved fatal. We performed an autopsy in accordance with the patient's wishes. Pathological findings revealed that all carcinomas in the thyroid, cervical lymph nodes, and lungs were pure SCCs. Immunohistochemical examinations for PAX8, thyroglobulin, and TTF-1 were all negative. Differentiated thyroid carcinomas have 3 major positive markers - PAX8, thyroglobulin, and TTF-1 –, and PAX8 is also sometimes positive for SCC in the thyroid. PAX8 positivity of SCC in the thyroid might, however, be associated with conjunction with other histological adenocarcinomas such as papillary or follicular thyroid carcinoma; therefore, pure SCC in the thyroid might be negative for PAX8.

Primary squamous cell carcinoma of the thyroid associated with papillary thyroid carcinoma and Hashimoto's thyroiditis

INTRODUCTION

We report the first case of squamous cell carcinoma (SCC) of the thyroid gland coexisting with papillary thyroid carcinoma (PTC) and Hashimoto's thyroiditis and discuss various theories concerning the histogenesis of SCC of the thyroid gland and the optimal treatment strategy.

CASE REPORT

A 54-year-old woman presented with an anterior neck mass measuring 4cm on clinical examination. Imaging showed a suspicious thyroid nodule invading the trachea. Total thyroidectomy with bilateral central lymph node resection was performed. Histological examination revealed tall cell variant of papillary thyroid carcinoma associated with SCC of the right lobe of the thyroid and Hashimoto's thyroiditis. Immunohistochemistry of the SCC showed positive staining for p53 and Ki67 and negative staining for thyroglobulin. The patient underwent adjuvant radioactive iodine therapy and radiotherapy. With postoperative follow-up of 24 months, the patient was in good health.

DISCUSSION

In conclusion, the most probable origin of SCC in this case was malignant transformation from Hashimoto's thyroiditis following a phase of metaplasia. This immunohistological profile is associated with a better prognosis. Optimal treatment consists of extensive surgical resection of tumour tissuefollowed by radiotherapy.

Primary squamous cell carcinoma of the thyroid: Case report and systematic review of the literature

BACKGROUND

Primary squamous cell cancer (PSCC) of thyroid is a rare malignancy with poor prognosis. It is mandatory to exclude secondary involvement of the thyroid by panendoscopy, CT-scan and immunohistochemical analysis. As treatment surgery, radiation and rarely chemotherapy is employed.

METHODS

A systematic review of the literature was conducted searching medline and embase database using the medical subject headings "primary squamous cell carcinoma of thyroid" and "primary squamous cell cancer of thyroid", for articles published until April 2016 (n=1733). Of interest were the used treatment modalities and survival outcomes.

RESULTS

A total of 35 publications reporting on 50 cases including ours were finally analyzed. A curative treatment approach was described in 24 patients (48%). Additional radiotherapy, chemotherapy or radiochemotherapy was applied in 17, 7 and 7 patients respectively. Median overall survival was 6 months [range 0-48] for 47 patients. Disease free survival was only achieved in 8 patients with disease limited to the thyroid gland, complete surgical resection and additional radiotherapy or radiochemotherapy [reported median 20 months; range 12-48].

CONCLUSION

Reported disease free survival of PSCC of the thyroid was only achieved in patients with complete surgical resection in combination with adjuvant radio- and/or chemotherapy. However long term survival has not been reported in the literature yet.

Primary Squamous Cell Carcinoma of the Thyroid: A Population-Based Analysis

Objectives To analyze the epidemiology and describe the prognostic indicators of patients with primary squamous cell carcinoma of the thyroid. Study Design and Setting Retrospective cohort study based on a national database. Methods The US National Cancer Institute's SEER registry (Surveillance, Epidemiology, and End Results) was reviewed for patients with primary squamous cell carcinoma of the thyroid from 1973 to 2012. Study variables included age, sex, race, tumor size, tumor grade, regional and distant metastases, and treatment modality. Survival measures included overall survival (OS) and disease-specific survival (DSS). Results A total of 199 cases of primary squamous cell carcinoma of the thyroid were identified. Mean age at diagnosis was 68.1 years; 58.3% were female; and 79.4% were white. Following diagnosis, 46.3% of patients underwent surgery; 55.7%, radiation therapy; and 45.8%, surgery with radiation therapy. Kaplan-Meier analysis demonstrated OS and DSS of 16% and 21% at 5 years, respectively. Median survival after diagnosis was 9.1 months. Multivariate Cox regression analysis showed that predictors of OS and DSS included age ( P < .001, P < .001, respectively), tumor grade ( P < .001, P = .001), and tumor size ( P < .001, P = .001). Surgical management was a predictor of OS but not DSS. Conclusion Squamous cell carcinoma of the thyroid is a rare malignancy with a very poor prognosis. Surgical resection confers an overall survival benefit. Age, tumor grade, and tumor size are predictors of OS and DSS.

Cardiac metastasis of squamous cell carcinoma of the thyroid gland with severe disseminated intravascular coagulation: A case report

Distant metastasis of primary squamous cell carcinoma (SCC) of the thyroid gland is rare and, to the best of our knowledge, cardiac metastasis has not been reported to date. A 57-year-old man underwent surgery and adjuvant chemoradiotherapy for stage IVA SCC of the thyroid gland. After 3 months, the patient was admitted to the Kyushu University Hospital (Fukuoka, Japan) with subcutaneous hematomas of the left thigh and lower leg, and he was diagnosed with cardiac and mediastinal lymph node metastases of SCC of the thyroid gland with severe disseminated intravascular coagulation (DIC). Echocardiography revealed a mass, 52 mm in greatest diameter, protruding from the interventricular septum towards the right ventricle. Weekly administration of paclitaxel and concurrent irradiation of the cardiac and lymph node metastases were performed. Eighteen days after the initiation of chemoradiotherapy, the DIC and hematomas had significantly improved, and the cardiac metastasis was stable. However, 2 months after admission, the patient developed dyspnea and multiple nodular shadows appeared to be spreading in the subpleura of the lungs bilaterally, which were initially suspected to be pulmonary tumor embolisms. Prednisolone and subsequent administration of lenvatinib were not effective and the patient succumbed to respiratory failure. Severe DIC caused by extremely rare cardiac metastasis of SCC of the thyroid gland was effectively controlled by chemoradiotherapy. However, intensive local control appears to be required for this condition.

Primary squamous cell carcinoma of the thyroid with complete response to radical radiotherapy and concurrent cisplatin-based chemotherapy

Chemoradiotherapy and/or surgery are both potentially radical treatments for squamous cell carcinomas. Squamous cell carcinomas are considered chemosensitive tumours compared to adenocarcinomas or anaplastic thyroid malignancies. A 76-year-old man was found to have T4bN0M0 primary squamous cell carcinoma of the thyroid with encasement of the internal carotid artery. The disease was deemed unresectable. Therefore, he was treated with radical radiotherapy with concurrent cisplatin-based chemotherapy. We discuss herein the aetiology, diagnosis and management of primary squamous cell carcinoma of the thyroid. We demonstrate success of chemoradiotherapy in an unresectable case of a rare and aggressive disease.

[Lymph node and distant metastases of thyroid gland cancer. Metastases in the thyroid glands]

The different biological features of the various major entities of thyroid cancer, e.g. papillary, follicular, poorly differentiated, anaplastic and medullary, depend to a large extent on their different metastatic spread. Papillary thyroid cancer (PTC) has a propensity for cervical lymphatic spread that occurs in 20-50 % of patients whereas distant metastasis occurs in < 5 % of cases. Cervical lymphadenopathy may be the first symptom particularly of (micro) PTC. In contrast follicular thyroid cancer (FTC) has a marked propensity for vascular but not lymphatic invasion and 10-20 % of FTC develop distant metastases. At the time of diagnosis approximately one third of medullary thyroid cancer (MTC) cases show lymph node metastases, in 10-15 % distant metastases and 25 % develop metastases during the course of the disease. Poorly differentiated (PDTC) and anaplastic thyroid cancer (ATC) spread via both lymphatic and vascular invasion. Thus distant metastases are relatively uncommon in DTC and when they occur, long-term stable disease is the typical clinical course. The major sites of distant metastases are the lungs and bone. Metastases to the brain, breasts, liver, kidneys, muscle and skin are relatively rare or even rare. The thyroid gland itself can be a site of metastases from a variety of other tumors. In autopsy series of patients with disseminated cancer disease, metastases to the thyroid gland were found in up to 10 % of cases. Metastases from other primary tumors to the thyroid gland have been reported in 1.4-3 % of patients who have surgery for suspected cancer of the thyroid gland. The most common primary cancers that metastasize to the thyroid gland are renal cell (48.1 %), colorectal (10.4 %), lung (8.3 %) and breast cancer (7.8 %) and surprisingly often sarcomas (4.0 %).

Primary Squamous Cell Carcinoma of Thyroid: A Rare Entity

Primary squamous cell carcinoma (PSCC) of thyroid is an extremely rare malignancy of thyroid. Herewith, we describe a case report of female patient who presented with neck swelling; FNAC misdiagnosed it as papillary carcinoma of thyroid but, after resection, biopsy revealed it to be a case of squamous cell carcinoma of thyroid. After extensive investigations no possible primary focus of squamous cell carcinoma was found elsewhere, so diagnosis of primary squamous cell carcinoma of thyroid was made. Patient underwent chemoradiation but still patient succumbed to death within a year.

Primary squamous cell carcinoma of the thyroid gland

Primary squamous cell carcinoma (SCC) of the thyroid gland is a very rare entity representing <1% of all primary carcinomas of the thyroid gland with a very poor prognosis. We report a rare case of a 65-year-old woman with SCC of the thyroid gland, emphasizing the postoperative complications and poor prognosis of these patients. Surgical excision of primary SCC of the thyroid gland when possible is the optimal therapy. Chemo- and radiotherapy rarely have place in its treatment as this malignancy has a poor response to chemotherapy and in many cases is radio-resistant. Median survival of these patients is around 6 months.

Primary squamous cell carcinoma of the thyroid diagnosed as anaplastic carcinoma: failure in fine-needle aspiration cytology?

A case of primary squamous-cell carcinoma (SCC) of the thyroid which had been initially diagnosed as an anaplastic carcinoma (ATC) is described: female, 73 years old, with a fast-growing cervical nodule on the left side and hoarseness for 3 months. Ultrasonography showed a 4.5 cm solid nodule. FNA was compatible with poorly differentiated carcinoma with immunoreactivity for AE1/AE3, EMA. Thyroidectomy was performed. Histopathological examination showed a nonencapsulated tumor. Immunohistochemistry disclosed positivity for AE1/AE3, p53,p63, and Ki67. The diagnosis was ATC. A second opinion reported tumor consisting of squamous cells, with intense inflammatory infiltrate both in tumor and in the adjacent thyroid, with final diagnosis of SCC, associated with Hashimoto thyroiditis. No other primary focus of SCC was found. Patient has shown a 48-month survival period. Clinically, primary SCCs of the thyroid and ATCs are similar. The distinction is often difficult particularly when based on the cytological analysis of FNA material.

Primary squamous cell carcinomas in the thyroid gland: an individual participant data meta-analysis

Primary squamous cell carcinomas arising from the thyroid gland (SCCTh) is extremely rare diseases, which have never been fully studied. Thus, we performed a systematic review and individual participant data meta-analysis of published SCCTh cases, to understand the clinical characteristics and to identify the prognostic factors of primary SCCTh. A literature search was conducted within Medline, EMBASE, Cochrane library databases and KoreaMed using the following Medical Subject Headings (MeSH) keywords: “primary,” “squamous,” “carcinoma,” “cancer,” and “thyroid.” Eighty-four patients' individual data from 39 articles and five patients' data in our institute were selected for analysis (N = 89). The mean age at diagnosis was 63.0 years (range, 24–90) and female preponderance (M:F = 1:2) was noted. The commonest complaint was the anterior neck mass, followed by dyspnea or dysphagia, and extension to the adjacent structure was found in 72%. The median survival was 9.0 months (95% CI, 6.0–23.0) and 3-year survival rate (3YSR) was 37.6% by Kaplan–Meier method, but only 20.1% by a shared frailty model for adjusting heterogeneity. Complete resection (R0) of tumors was the only significant prognostic factor in multivariable analysis, and the benefit of adjuvant treatment was not proved. The prognosis of patients with SCCTh is very poor (20% in 3YSR), but complete resection of disease is correlated with improved survival. To achieve complete surgical eradication of tumors, early detection and accurate diagnosis should be emphasized.

Primary squamous cell of the thyroid-an abbreviated clinical presentation

BACKGROUND

Lacking any squamous epithelium, thyroid gland with primary squamous cell carcinoma (PSCC) proves to be an etiopathophysiological quandary. Two major theories do exist, though few cases have been documented to support either. We present a case that supports the "metaplasia" theory, which serves to enhance our understanding of a disease that carries with it a very poor prognosis.

CASE PRESENTATION

We present a case of an extremely advanced, primary squamous cell carcinoma of the thyroid with distant metastases in a thirty-six year-old male. Dying of airway compromise seventeen days following his admission, this is the shortest median survival of all documented cases.

CONCLUSION

In addition to being the most abbreviated time period between presentation and death of all documented thyroid primary squamous cell carcinomas, we share the fifth case of thyroid PSCC in the setting of lymphocytic thyroiditis. This case should build awareness of the aggressivity of the disease and the lack of established diagnostic criteria.

Laryngotracheal presentation of anaplastic thyroid carcinoma with squamous differentiation: seven cases demonstrating an under-recognized diagnostic pitfall

AIMS

To describe a series of anaplastic thyroid carcinomas that mimicked primary head and neck squamous cell carcinoma (HNSCC) by virtue of both morphology and clinical presentation.

METHODS AND RESULTS

Seven cases were identified in a 15-year period where a biopsy of an airway lesion that appeared to be squamous cell carcinoma was, in fact, anaplastic thyroid carcinoma. The tumours had squamous and/or spindle cell morphology, with only the squamous component being apparent in the airway biopsy. Some tumours arose within metaplastic (n = 3) or atypical (n = 3) epithelium, supporting the diagnosis of a primary mucosal tumour. Positive PAX8 (n = 5) and TTF-1 (n = 4) staining was identified.

CONCLUSIONS

An endotracheal presentation of anaplastic thyroid carcinoma with squamous morphology may be misdiagnosed as a primary head and neck squamous cell carcinoma. PAX8 and TTF-1 expression are helpful in making the distinction, but the problem lies in suspecting a thyroid carcinoma in what appears to be a straightforward diagnosis of HNSCC.

Papillary thyroid carcinoma recurring as squamous cell carcinoma 10 years after total thyroidectomy: lessons from rapidly progressive papillary thyroid carcinoma

Primary squamous cell carcinoma (SCC) of the thyroid is very rare. There are no reports of metastatic papillary thyroid carcinoma (PTC) converting to SCC in cervical lymph nodes following total thyroidectomy due to conventional PTC. An 86-year-old woman with a remote history of total thyroidectomy due to PTC underwent palliative neck surgery to treat recurrent bleeding originating from a metastatic tumor of the cervical lymph nodes. The resected mass was composed of mixed SCC and PTC. Although primary SCC rarely occurs in the thyroid, conversion of PTC to SCC should be suspected if preexisting PTC exhibits highly aggressive behavior.

[Primary squamous cell carcinoma of the thyroid gland]

Primary squamous cell carcinoma of the thyroid gland is a rare form of cancer. As part of the differential diagnosis, metastases or direct extension from an extra-thyroidal primary tumor must always be ruled out. We report on a 59-year-old patient presenting with a 3.9-cm cold nodule on thyroid scintigraphy. A total thyroidectomy was performed and the final histopathological evaluation revealed an undifferentiated, primary squamous cell carcinoma of the thyroid gland, tumor stage pT2 pN0 (0/56), L0 V0 R0. On the basis of the R0 resection, tumor size and negative nodal status, we recommended regular postoperative follow-up examinations without adjuvant radiochemotherapy.

Primary squamous cell carcinoma of the thyroid gland: a case report and review

BACKGROUND

Primary squamous cell carcinoma (SCC) of the thyroid gland is a rare malignancy that presents with advanced disease and poor prognosis.

METHODS

A 75-year-old woman with a history of Hashimoto thyroiditis presented with 6 months of dysphagia and stridor. Imaging revealed a thyroid mass invading the larynx. Primary SCC of the thyroid was diagnosed by histopathologic and immunohistochemical evaluation. Total thyroidectomy, total laryngectomy, bilateral modified neck dissection, and adjuvant radiotherapy (RT) were performed. Radiologic follow-up at 21 months demonstrated no disease and total length of survival was 31 months.

RESULTS

Despite an aggressive T4aN0M0 tumor, survival in this case was more than double the median survival rate previously reported. Concomitant Hashimoto thyroiditis is rare and histopathologic and immunohistochemical evaluation is imperative for an accurate diagnosis.

CONCLUSION

The case and literature reported here support that a thorough diagnostic workup of primary SCC of the thyroid with aggressive locoregional surgery and adjuvant RT may improve the length of survival.

Clinical trial of weekly paclitaxel chemotherapy for papillary thyroid carcinoma with squamous cell carcinoma component

Papillary thyroid carcinoma (PC) can occasionally include a squamous cell carcinoma (SCC) component. In this study, we evaluated the effect of weekly paclitaxel chemotherapy in 3 patients with PC including an SCC component. None of these patients had lesions of anaplastic carcinoma on pathological examination. Weekly paclitaxel chemotherapy was performed as an induction chemotherapy for 2 patients. All 3 patients underwent locally curative surgery and weekly paclitaxel chemotherapy after surgery as an adjuvant therapy. The response to the chemotherapy was evaluated based on the RECIST guideline (version 1.1). Two patients had partial responses (PRs) and the remaining 1 had stable disease (SD). The response rate was 67% and the clinical benefit rate (PR+SD) was 100%. One patient died of the growth of lung metastases that had been detected before surgery 22 months after the diagnosis. The remaining 2 are still alive, 14 and 22 months after the diagnosis, respectively. Taken together, weekly paclitaxel may be one of the effective adjuvant therapies for PC with an SCC component.

Biological behavior of papillary carcinoma of the thyroid including squamous cell carcinoma components and prognosis of patients who underwent locally curative surgery

Thyroid carcinoma showing squamous differentiation throughout the entire lesion is diagnosed as squamous cell carcinoma of the thyroid (SCCT) in the WHO classification. This entity is a rare disease and shows a dire prognosis; however, squamous differentiation is more frequently detected in only a portion of papillary thyroid carcinoma. In this paper, we present our experience of 10 patients (8 primary lesions and 2 with recurrence in the lymph nodes) with papillary thyroid carcinoma having an SCC component (PTC-SCC). Only 3 of 8 primary lesions (38%) and none of the 2 recurrent nodes were preoperatively diagnosed as or suspected of having SCC components. All 10 patients underwent locally curative surgery. To date, 3 patients have died of carcinoma, and 2 had distant metastasis at diagnosis or had an undifferentiated carcinoma component. The other 7 are currently alive 5 to 43 months after diagnosis. Systemic adjuvant therapy after the detection of recurrence was effective for 2 patients. It is possible that some PTC-SCC patients without distant metastasis who undergo locally curative surgery can survive for a prolonged period and adjuvant therapies can be effective for local and distant recurrences.